HELP! I have an enormous amount of small thin stains on the floor of my pool, most 1 to 2 inches long. A few on the steps (photo: appear to be dark orange/brown), none on walls, tons on floor; generally an inch or two long. They do not brush out (wire brush). They first appeared end of last season, and still there with this year opening (hundreds). I am in Farmington Hills, Michigan, water is from well however run through softener and iron removal system. And identification or removal ideas appreciated.
They look like it could be something that blew into the pool, staples from a roofing material, wire bristles if a brush fell apart? Bobby pins make stains like that too, and it can happen in just a day or two. Metal shavings if anything was cut near the pool or if metal was drilled through? If something sits long enough they can break down and cause staining. To remove metal stains StainFree https://amzn.to/4dALmtD usually works. If stains are organic, then chlorine or muriatic acid take them out- like if they were pine needle or leaf stains etc.
If you only had one or two spots sometimes it is rebar leeching through the pool finish – but in your case I would guess something that blew into the pool or fell in and sunk to the bottom.
Good luck!